Thanks @backtrader for the clarification. With regards to what you said, that means I cannot cancel the order once the instance has changed. For example, I can no longer cancel order 581 and 582 after the order 583 is executed.

@ backtrader. How to cancel all the pending stop and limit order by end of the day which is not executed due to the market price not reaching the order price level.

Is there any way to cancel all such order without passing order.ref as an argument if this is not possible
*How do I retrieve order.ref for all the pending order programmatically. Example code will be appreciable